Lamp support arm



FIG. 1 is a side elevation view of the lamp support arm illustrating the environment of the support arm in accordance with my design;

FIG. 2 is a top plan view of the lamp support arm in accordance with my design;

FIG. 3 is a rear elevation view of the lamp support arm in accordance with my design;

FIG. 4 is a side elevation view of the lamp support arm in accordance with my design;

FIG. 5 is a front elevation view of the lamp support arm in accordance with my design; and,

FIG. 6 is a bottom plan view of the lamp support arm in accordance with my design.

The left and right elevational views are symmetrical.

The broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for the lamp support arm, as shown and described. 